This view of "Vera Rubin Ridge" from the ChemCam instrument on NASA's Curiosity Mars rover shows sedimentary layers and fracture-filling mineral deposits. ChemCam's telescopic Remote Micro-Imager took the 10 component images of this scene on July 3, 2017, from a distance of about 377 feet.

Researchers used the Mastcam on NASA's Curiosity Mars rover to gain this detailed view of layers in "Vera Rubin Ridge" from just below the ridge. The scene combines 70 images taken with the Mastcam's right-eye, telephoto-lens camera, on Aug. 13, 2017.

Researchers used the Mastcam on NASA's Curiosity Mars rover to gain this detailed view of layers in "Vera Rubin Ridge" from just below the ridge. The scene combines 70 images taken with the Mastcam's right-eye, telephoto-lens camera, on Aug. 13, 2017.

"Vera Rubin Ridge," a favored destination for NASA's Curiosity Mars rover even before the rover landed in 2012, rises near the rover nearly five years later in this panorama from Curiosity's Mast Camera (Mastcam).

"Vera Rubin Ridge," a favored destination for NASA's Curiosity Mars rover even before the rover landed in 2012, rises near the rover nearly five years later in this panorama from Curiosity's Mastcam. The scene combines 23 images taken with the Mastcam's right-eye camera, on June 22, 2017.

Five years since it landed near Mount Sharp on Mars in August 2017 and nearly three years since reaching the base of the mountain, NASA's Curiosity Mars rover is climbing toward multiple layers of Mount Sharp visible in this view from the rover's Mast Camera.

This map shows the route driven by NASA's Curiosity Mars rover, from the location where it landed in August 2012 to its location in July 2017 (Sol 1750), and its planned path to additional geological layers of lower Mount Sharp.

A rippled linear dune of dark Martian sand, "Nathan Bridges Dune," dominates this full-circle panorama from the Mastcam of NASA's Curiosity Mars rover. This dune was one research stop of the mission's campaign to investigate active Martian dunes. Nathan Bridges (1966-2017) helped lead that campaign

This view from the Curiosity Mars rover's Mastcam shows a dark mound, called "Ireson Hill," which rises about 16 feet above redder layered outcrop material on lower Mount Sharp, Mars, near a location where Curiosity examined a linear sand dune in February 2017.

This panorama from the Mast Camera (Mastcam) of NASA's Curiosity Mars rover shows details of "Vera Rubin Ridge," which stretches about 4 miles (6.5 kilometers), end-to-end, on the northwestern flank of lower Mount Sharp.

This early 2017 look ahead from the Mastcam of NASA's Curiosity Mars rover includes four geological layers to be examined by the mission, and higher reaches of Mount Sharp beyond the planned study area. "Vera Rubin Ridge" sits just above the reddish foreground rocks of the Murray formation.

This is how AEGIS sees the Martian surface. All targets found by the A.I. program are outlined: blue targets are rejected, while red are retained. The top-ranked target is shaded green; if there's a second-ranked target, it's shaded orange. These NavCam images have been contrast-balanced.

The feature that appears bright blue at the center of this scene is NASA's Curiosity Mars rover on the northwestern flank of Mount Sharp, viewed by NASA's Mars Reconnaissance Orbiter. Curiosity is approximately 10 feet long and 9 feet wide (3.0 meters by 2.8 meters).

This view from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows two scales of ripples, plus other textures, in an area where the mission examined a linear-shaped dune in the Bagnold dune field on lower Mount Sharp in March and April 2017.

This 360-degree scene from the Mastcam on NASA's Curiosity Mars rover includes part of a linear-shaped dune the rover examined in early 2017 for comparison with what it found previously at crescent-shaped dunes. The view shows the dark, rippled surface of the active dune, near sedimentary bedrock.

Two of the raised treads, called grousers, on the left middle wheel of NASA's Curiosity Mars rover broke during the first quarter of 2017, including the one seen partially detached at the top of the wheel in this image from the Mars Hand Lens Imager (MAHLI) camera on the rover's arm.

Dust devils dance in the distance in this sequence of images taken by the Navigation Camera on NASA's Curiosity Mars rover on Feb. 12, 2017, during the afternoon of the rover's 1,607th Martian day, or sol.

Beyond a dark sand dune closer to the rover, a Martian dust devil passes in front of the horizon in this sequence of images from NASA's Curiosity Mars rover. The rover's Navigation Camera made this series of observations on Feb. 4, 2017, during the local afternoon in Mars' Gale Crater.

This sequence of images shows a dust-carrying whirlwind, called a dust devil, scooting across ground inside Gale Crater, as observed on the local summer afternoon of NASA's Curiosity Mars Rover's 1,597th Martian day, or sol (Feb. 1, 2017). Timing is accelerated in this animation.

This map shows the two locations of a research campaign by NASA's Curiosity Mars rover mission to investigate active sand dunes on Mars. In late 2015, Curiosity reached crescent-shaped dunes, called barchans. In February 2017, the rover reached a location where the dunes are linear in shape.

The left side of this 360-degree panorama from NASA's Curiosity Mars rover shows the long rows of ripples on a linear shaped dune in the Bagnold Dune Field on the northwestern flank of Mount Sharp. The rover's Navigation Camera recorded the component images of this mosaic on Feb. 5, 2017.

This pair of images shows effects of one Martian day of wind blowing sand underneath NASA's Curiosity Mars rover on a non-driving day for the rover. Each image was taken just after sundown by the rover's Mars Descent Imager (MARDI). The area of ground shown spans about 3 feet left-to-right.

A grid of small polygons on the Martian rock surface near the right edge of this view may have originated as cracks in drying mud more than 3 billion years ago. Multiple Dec. 20, 2016, images from the Mastcam on NASA's Curiosity Mars rover were combined for this view of a rock called "Squid Cove."

This view of a Martian rock slab called "Old Soaker," which has a network of cracks that may have originated in drying mud, comes from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover. It was taken on Dec. 20, 2016. The slab is about 4 feet long.

The network of cracks in this Martian rock slab called "Old Soaker" may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 3 feet (90 centimeters) left-to-right and combines three images taken by the MAHLI camera on the arm of NASA's Curiosity Mars rover.

This pair of drawings depicts the same location at Gale Crater on at two points in time: now and billions of years ago. Water moving beneath the ground, as well as water above the surface in ancient rivers and lakes, provided favorable conditions for microbial life, if Mars has ever hosted life.

The foreground of this scene from the Mastcam on NASA's Curiosity Mars rover shows purple-hued rocks near the rover's late-2016 location. The middle distance includes future destinations for the rover. Variations in color of the rocks hint at the diversity of their composition on lower Mount Sharp.

This graphic maps locations of the sites where NASA's Curiosity Mars rover collected its first 19 rock or soil samples for laboratory analysis inside the vehicle. It also presents images of the drilled holes where 15 rock-powder samples were acquired, most recently at "Sebina," on Oct. 20, 2016.

Examination of a calcium sulfate vein called "Diyogha" by the ChemCam instrument on NASA's Curiosity Mars rover found boron, sodium and chlorine. An image from the rover's Mastcam, at left, provides context for the magnified image and composition information from ChemCam, at right.

The highest concentration of boron measured on Mars, as of late 2016, is in this mineral vein examined with the ChemCam instrument on NASA's Curiosity rover on Aug, 25, 2016. Orange bars indicate boron content at points in the calcium sulfate vein. The context image is from Curiosity's Mastcam.

This map shows the route driven by NASA's Curiosity Mars rover (blue line) and locations where the rover's ChemCam instrument detected the element boron (dots, colored by abundance of boron according to the key at right). The inset is a blowup of the most recent portion of the traverse.

This graphic shows proportions of minerals identified by the Curiosity Mars rover's CheMin instrument in mudstone outcrops at "Yellowknife Bay" in 2013 and at "Murray Buttes" in 2016. For example, the rover found more hematite and less magnetite at Murray Buttes, compared with Yellowknife Bay.

This graphic illustrates how dimensions of clay minerals' crystal structure are affected by which ions are present in the mineral. The CheMin instrument on NASA's Curiosity Mars rover identified different clay minerals this way at two sites in Gale Crater: "Murray Buttes" and "Yellowknife Bay."

Data graphed here from the Chemistry and Camera (CheMin) instrument on NASA's Mars Curiosity rover show a difference between clay minerals in powder drilled from mudstone outcrops at two locations in Mars' Gale Crater: "Yellowknife Bay" and "Murray Buttes."

This series of pie charts shows similarities and differences in the mineral composition of mudstone at 10 sites where NASA's Curiosity Mars rover collected rock-powder samples and analyzed them with the rover's Chemistry and Mineralogy (CheMin) instrument.

This graphic depicts aspects of the driving distance, elevation, geological units and time intervals of NASA's Curiosity Mars rover mission, as of late 2016. The vertical dimension is exaggerated 14-fold compared with the horizontal dimension, for presentation-screen proportions.

This map shows the route driven by NASA's Curiosity Mars rover from the location where it landed in August 2012 to its location in December 2016, which is in the upper half of a geological unit called the Murray Formation, on lower Mount Sharp.

This Dec. 2, 2016, view from the Navigation Camera (Navcam) on the mast of NASA's Curiosity Mars Rover shows rocky ground within view while the rover was working at an intended drilling site called "Precipice" on lower Mount Sharp.

A NASA radio on Europe's Trace Gas Orbiter, which reached Mars in October 2016, has succeeded in its first test of receiving data from NASA Mars rovers, both Opportunity and Curiosity. This graphic depicts the geometry of the relay from Opportunity to the orbiter, which then sent the data to Earth.

The dark, smooth-surfaced rock at the center of this Oct. 30, 2016, image from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover was examined with laser pulses and confirmed to be an iron-nickel meteorite. It is about the size of a golf ball.

The dark, golf-ball-size object in this composite, colorized view from the ChemCam instrument on NASA's Curiosity Mars rover is a nickel-iron meteorite, as confirmed by analysis using laser pulses from ChemCam on Oct. 30, 2016. The grid of bright spots on the rock resulted from the laser pulses.

This September 2016 self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Quela" drilling location in the scenic "Murray Buttes" area on lower Mount Sharp. The panorama was stitched together from multiple images taken by the MAHLI camera at the end of the rover's arm.

This 360-degree panorama was acquired on Sept. 4, 2016, by the Mast Camera on NASA's Curiosity Mars rover while the rover was in a scenic area called "Murray Buttes" on lower Mount Sharp. The flat-topped mesa near the center of the scene rises to about 39 feet above the surrounding plain.

This map shows the route driven by NASA's Curiosity Mars rover from the location where it landed in August 2012 to its location in September 2016 at "Murray Buttes," and the path planned for reaching destinations at "Hematite Unit" and "Clay Unit" on lower Mount Sharp.

This graphic maps locations of the sites where NASA's Curiosity Mars rover collected its first 18 rock or soil samples for laboratory analysis inside the vehicle. It also presents images of the drilled holes where 14 rock-powder samples were acquired, most recently at "Quela," on Sept. 18, 2016.

The top of the butte in this Sept. 1, 2016, scene from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover stands about 16 feet above the rover and about 82 feet east-southeast of the rover. The site is in the "Murray Buttes" area of lower Mount Sharp, and this particular butte is called "M9a."

The mesa in the center of this scene from the "Murray Buttes" area on Mars is longer than a football field. The panorama combines images taken by the Mastcam on NASA's Curiosity Mars rover on Aug. 22 and Aug. 23, 2016.

The two prominent mesas in this Aug. 18, 2016, view of Mars' "Murray Buttes" region from the Curiosity Mars rover's Mastcam are about 260 feet (about 80 meters) apart. The one on the right is about 33 feet high, and its top is about 270 feet from the rover's position when the images were taken.

Apollo 11 astronaut Buzz Aldrin, left, and Erisa Hines of NASA's Jet Propulsion Laboratory in Pasadena, California, speak to members of the news media during a preview of the new "Destination: Mars" experience at the Kennedy Space Center visitor complex in Florida.

This 360-degree vista was acquired on Aug. 5, 2016, by the Mastcam on NASA's Curiosity Mars rover as the rover neared features called "Murray Buttes" on lower Mount Sharp. The dark, flat-topped mesa seen to the left of the rover's arm is about 50 feet high and, near the top, about 200 feet wide.

This July 22, 2016, stereo scene from the Mastcam on NASA's Curiosity Mars Rover shows boulders at a site called "Bimbe" on lower Mount Sharp. They contain pebble-size and larger rock fragments. The image appears three dimensional when viewed through red-blue glasses with the red lens on the left.

This 360-degree vista was acquired on Aug. 5, 2016, by the Mastcam on NASA's Curiosity Mars rover as the rover neared features called "Murray Buttes" on lower Mount Sharp. The dark, flat-topped mesa seen to the left of the rover's arm is about 50 feet high and, near the top, about 200 feet wide.

NASA's Curiosity Mars rover began close-up investigation of a target called "Marimba," on lower Mount Sharp, during the week preceding the fourth anniversary of the mission's Aug. 6, 2016, landing. Curiosity's Navigation Camera took this shot of the rover's arm over Marimba on Aug. 2, 2016.

NASA's Curiosity Mars rover autonomously selects some targets for the laser and telescopic camera of its ChemCam instrument. For example, on-board software analyzed the Navcam image at left, chose the target indicated with a yellow dot, and pointed ChemCam for laser shots and the image at right.

Two sizes of ripples are evident in this Dec. 13, 2015, view of a top of a Martian sand dune, from NASA's Curiosity Mars rover. Sand dunes and the smaller type of ripples also exist on Earth. The larger ripples are a type not seen on Earth nor previously recognized as a distinct type on Mars.

This scene shows NASA's Curiosity Mars rover at a location called "Windjana," where the rover found rocks containing manganese-oxide minerals, which require abundant water and strongly oxidizing conditions to form.

This graphic maps the first 14 sites where NASA's Curiosity Mars rover collected rock or soil samples for analysis using the rover's onboard laboratory. It also presents images of the drilled holes where 12 rock-powder samples were acquired. At the other two sites Curiosity scooped soil samples.

The top of the rover's mast faces away in this May 11, 2016, self-portrait of NASA's Curiosity Mars rover, which shows the vehicle at the "Okoruso" drilling site on lower Mount Sharp. The scene is a mosaic of multiple images taken with the arm-mounted Mars Hands Lens Imager (MAHLI).7856

This May 11, 2016, self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Okoruso" drilling site on lower Mount Sharp's "Naukluft Plateau." The scene is a mosaic of multiple images taken with the arm-mounted Mars Hands Lens Imager (MAHLI).

This animated image blinks two versions of a May 11, 2016, selfie of NASA's Curiosity Mars rover at a drilled sample site called "Okoruso." In one version, cameras atop the rover's mast face the arm-mounted camera taking the portrait. In the other, they face away.

NASA's Curiosity Mars rover measures the concentration of methane in the atmosphere at Gale Crater. A one-time spike in methane, up to about 7 parts per billion occurred during Curiosity's first Martian year. Variations in much lower background levels of methane may be seasonal.

By monitoring weather through two Martian years since landing in Gale Crater, NASA's Curiosity Mars rover has documented seasonal patterns in variables such as temperature, water-vapor content and air pressure. Each Mars year lasts nearly two Earth years.

By monitoring weather through two Martian years since landing in Gale Crater, NASA's Curiosity Mars rover has documented seasonal patterns in variables such as temperature, water-vapor content and air pressure. Each Mars year lasts nearly two Earth years.

This early-morning view from the Mastcam on NASA's Curiosity Mars rover on March 16, 2016, covers a portion of the inner wall of Gale Crater. At right, the image fades into glare of the rising sun. Details such as gullies and debris fans help geologists understand processes that shaped the crater.

This 360-degree panorama from the Mastcam on NASA's Curiosity Mars rover shows the rugged surface of 'Naukluft Plateau' plus upper Mount Sharp at right and part of the rim of Gale Crater. The April 4, 2016, scene is dominated by eroded remnants of a finely layered ancient sandstone deposit.

This 360-degree panorama from the Mastcam on NASA's Curiosity Mars rover shows the rugged surface of 'Naukluft Plateau' plus upper Mount Sharp at right and part of the rim of Gale Crater. The April 4, 2016, scene is dominated by eroded remnants of a finely layered ancient sandstone deposit.

The nodule in the center of this March 10, 2016, image from the Mars Hand Lens Imager (MAHLI) on NASA's Curiosity Mars rover shows individual grains of sand and (on the right) laminations from the sandstone deposit in which the nodule formed..

Patches of Martian sandstone visible in the lower-left and upper portions of this view from the Mast Camera (Mastcam) of NASA's Curiosity Mars rover have a knobbly texture due to nodules apparently more resistant to erosion than the host rock in which some are still embedded.

Patches of Martian sandstone visible in the lower-left and upper portions of this view from the Mast Camera (Mastcam) of NASA's Curiosity Mars rover have a knobbly texture due to nodules apparently more resistant to erosion than the host rock in which some are still embedded.

This map shows the route driven by NASA's Curiosity Mars rover from where it landed in 2012 to its location in early March 2016, approaching 'Naukluft Plateau.' As the rover continues up Mount Sharp, its science team has been refreshed by a second round of NASA participating-scientist selections.

The Mars Hand Lens Imager (MAHLI) camera on the robotic arm of NASA's Curiosity Mars rover used electric lights at night on Jan. 22, 2016, to illuminate this postage-stamp-size view of Martian sand grains dumped on the ground after sorting with a sieve.

This Jan. 19, 2016, self-portrait of NASA's Curiosity Mars rover shows the vehicle at "Namib Dune," where the rover's activities included scuffing into the dune with a wheel and scooping samples of sand for laboratory analysis.